Rear Crankshaft Oil Seal 1111 7587 168 For BMW Engine Parts

1. Product Name & Function

• English Name: Rear Crankshaft Oil Seal (also known as Rear Main Seal)

• Purpose: Installed at the rear end of the engine crankshaft (transmission side) to prevent engine oil leakage from the crankcase while blocking external dust, moisture, and contaminants from entering the engine.

2.Compatibility Chart

3. Technical Specifications & Materials

• Seal Type: Dual-lip design (main sealing lip + dust lip)

• Materials:

  • Sealing Lip: Fluoroelastomer (FKM/Viton), resistant to high temperatures (-30°C to +250°C), oil, and fuel.

  • Housing: High-strength steel or aluminum for a secure crankcase fit.

• Dimensions (example, actual may vary):

  • Inner Diameter (ID): ~80-90mm (matches crankshaft journal)

  • Outer Diameter (OD): ~100-110mm

  • Thickness: ~10-12mm

4. Key Features

• OEM-Quality: Meets BMW OEM standards for precise fit and sealing.
• Longevity: FKM material resists aging, with a service life of 80,000–100,000 km (normal conditions).
• Leak Prevention: Dual-lip + spring reinforcement for crankshaft eccentricity/vibration tolerance.
• Compatibility: Works with factory oils (e.g., BMW LL-01/LL-04) and synthetic blends.

5. Replacement Guide & Notes

    When to Replace?

• Oil leaks at the engine-transmission junction (drips or residue).

• During transmission/flywheel removal (preventive maintenance).

• Engine overhaul or high-mileage servicing (e.g., 150,000+ km).

    Installation Tips

1. Professional Service: Requires transmission/flywheel removal; best done by a technician.

2. Surface Prep: Clean the crankshaft contact area; check for wear/scratches (may cause re-leakage).

3. Lubrication: Apply oil or sealant to the lip before installation to prevent dry friction damage.

4. Tools: Use a seal driver (e.g., BMW specialty tools) to avoid deformation.

6. FAQs

 Q: How to diagnose a failing seal?

• A: Look for oil stains near the transmission or abnormal oil consumption.

 Q: Can it be replaced without removing the transmission?

• A: Rarely—most applications require transmission/flywheel disassembly.